Abstract: A method for transporting inventory items includes moving a mobile drive unit to a first point within a workspace. The first point is a location of an inventory holder. The method further includes docking the mobile drive unit with the inventory holder and moving the mobile drive unit and the inventory holder to a second point within the workspace. The second point is associated with conveyance equipment. The method further includes moving the inventory holder to a third point within the workspace using the conveyance equipment.

Abstract: A method for transporting inventory items includes moving a mobile drive unit to a first point within a workspace. The first point is a location of an inventory holder. The method further includes docking the mobile drive unit with the inventory holder and moving the mobile drive unit and the inventory holder to a second point within the workspace. The second point is associated with conveyance equipment. The method further includes moving the inventory holder to a third point within the workspace using the conveyance equipment.

Abstract: A method for retrieving inventory items within an inventory system includes receiving a retrieval request that identifies an inventory item and selecting, from a plurality of inventory stations, an inventory station to fulfill an order associated with the retrieval request. The method also includes selecting an inventory holder from a plurality of inventory holders that store the inventory item and selecting, from a plurality of mobile drive units, a mobile drive unit to move the selected inventory holder to the selected inventory station.

Abstract: A method for storing inventory items in an inventory system includes receiving a replenish request identifying an inventory item to be stored in an inventory system and determining a classification of the inventory item to be stored. The method also includes selecting an inventory holder from a plurality of inventory holders based, at least in part, on the classification of the inventory item to be stored and a classification of one or more other inventory items currently stored in the selected inventory holder. Additionally, the method includes transmitting information identifying the selected inventory holder to a mobile drive unit.

Abstract: A system for transporting inventory items includes an inventory holder capable of storing inventory items and a mobile drive unit. The mobile drive unit is capable of moving to a first point with the inventory holder at least one of coupled to and supported by the mobile drive unit. The mobile drive unit is additionally capable of determining a location of the inventory holder and calculating a difference between the location of the inventory holder and the first point. The mobile drive unit is then capable of determining whether the difference is greater than a predetermined tolerance. In response to determining that the difference is greater than the predetermined tolerance, the mobile drive unit is also capable of moving to a second point based on the location of the inventory holder, docking with the inventory holder, and moving the mobile drive unit and the inventory holder to the first point.

Abstract: A method for moving a mobile drive unit within a workspace includes receiving a path. The path includes at least an initial segment and one or more additional segments. The initial segment includes a portion of the path adjacent to the first point; and at least one of the additional segments includes a portion of the path adjacent to the second point. The method further includes storing the path, reserving the initial segment of the path, and moving away from the first point along the initial segment. After initiating movement along the initial segment, the method includes reserving each of the additional segments of the path and moving toward the second point along each of the additional segments while that segment is reserved.

Abstract: An apparatus for transporting inventory items includes a housing, a drive module, a docking module, an elevating shaft, and a rotation module. The drive module is capable of propelling the apparatus in at least a first direction. The docking head is capable of coupling to or supporting an inventory holder. The rotation module is capable of inducing rotation in the housing relative to the elevating shaft. The elevating shaft connects to the docking head and is capable of raising the docking head when the housing is rotated relative to the elevating shaft.

Abstract: A system for transporting inventory items includes an inventory holder capable of storing inventory items and a mobile drive unit. The mobile drive unit is capable of moving to a first point with the inventory holder at least one of coupled to and supported by the mobile drive unit. The mobile drive unit is additionally capable of determining a location of the inventory holder and calculating a difference between the location of the inventory holder and the first point. The mobile drive unit is then capable of determining whether the difference is greater than a predetermined tolerance. In response to determining that the difference is greater than the predetermined tolerance, the mobile drive unit is also capable of moving to a second point based on the location of the inventory holder, docking with the inventory holder, and moving the mobile drive unit and the inventory holder to the first point.

Abstract: A method for fulfilling requests in an inventory system includes receiving a request indicating an activity to be completed. The method also includes selecting a holder to fulfill the request and an inventory station at which to fulfill the request. The inventory station is associated with a queue that includes a plurality of queue spaces. The method further includes moving the selected holder from a first location to a second location remote from the selected inventory station. Additionally, the method also includes determining that a trigger event has occurred and, in response to determining that the trigger event has occurred, moving the selected holder from the second location to a queue space of a queue associated with the selected inventory station.

Abstract: A system for transporting inventory includes an inventory holder and a mobile drive unit. The inventory holder includes a frame capable of storing inventory items and a docking plate capable of receiving a docking head from underneath. The mobile drive unit, includes a docking head capable of coupling to the docking plate and a drive module capable of propelling the mobile drive unit. The mobile drive unit is further capable to move the inventory holder when the docking head is coupled to the inventory holder.

Abstract: A method for fulfilling inventory requests includes receiving an inventory request requesting an inventory item and selecting the requested inventory item from an inventory holder. The method further includes storing the requested inventory item in an order holder associated with the inventory request and moving the order holder to a storage space. In addition, the method includes detecting a triggering event and in response to detecting the triggering event, retrieving the order holder from the storage space.

Abstract: A method for communicating information pertaining to a task includes receiving wirelessly first status information. The first status information specifies a first status associated with a task. The method also includes indicating the first status to a user and receiving input from the user indicating a second status associated with the task. Additionally, the method includes transmitting wirelessly second status information to a remote device in response to receiving the input from the user. The second status information specifies the second status.

Abstract: An apparatus for transporting inventory items includes a housing, a drive module, a docking module, an elevating shaft, and a rotation module. The drive module is capable of propelling the apparatus in at least a first direction. The docking head is capable of coupling to or supporting an inventory holder. The rotation module is capable of inducing rotation in the housing relative to the elevating shaft. The elevating shaft connects to the docking head and is capable of raising the docking head when the housing is rotated relative to the elevating shaft.